From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17925 invoked by alias); 15 Jun 2006 07:53:40 -0000 Received: (qmail 17915 invoked by uid 22791); 15 Jun 2006 07:53:39 -0000 X-Spam-Check-By: sourceware.org Received: from mx1.redhat.com (HELO mx1.redhat.com) (66.187.233.31) by sourceware.org (qpsmtpd/0.31) with ESMTP; Thu, 15 Jun 2006 07:53:36 +0000 Received: from int-mx1.corp.redhat.com (int-mx1.corp.redhat.com [172.16.52.254]) by mx1.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k5F7rYUi023851; Thu, 15 Jun 2006 03:53:34 -0400 Received: from pobox.surrey.redhat.com (pobox.surrey.redhat.com [172.16.10.17]) by int-mx1.corp.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k5F7rXq3011888; Thu, 15 Jun 2006 03:53:34 -0400 Received: from [10.32.68.6] (vpn-68-6.surrey.redhat.com [10.32.68.6]) by pobox.surrey.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k5F7rXVF032408; Thu, 15 Jun 2006 08:53:33 +0100 Message-ID: <449111FC.8010909@redhat.com> Date: Thu, 15 Jun 2006 08:10:00 -0000 From: Nick Clifton User-Agent: Thunderbird 1.5 (X11/20051201) MIME-Version: 1.0 To: "H. J. Lu" CC: binutils@sources.redhat.com Subject: Re: PATCH: Add --alt-nops=short|long to x86/x86-64 assemblers References: <20060613190254.GB21884@lucon.org> <448FBB66.7040806@redhat.com> <20060614150158.GA30299@lucon.org> <449027CF.3070705@redhat.com> <20060614172000.GA31328@lucon.org> In-Reply-To: <20060614172000.GA31328@lucon.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes Mailing-List: contact binutils-help@sourceware.org; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sourceware.org X-SW-Source: 2006-06/txt/msg00236.txt.bz2 Hi H. J. > x86/x86-64 assemblers don't support -mtune/-march/-mcpu. Ahh. How does the assembler know which instruction set variants are valid then ? (I am thinking of the all the different SSE, PowerNow, etc variants). > We need a switch to tell > assembler if the new nop instructions can be used at all. Secondly, > not all modern processors prefer "long" versions. We need another > switch to tell which kind of the new nop instructions should be used, > short or long. In which case the default presumably ought to be the short version and the long version should only be enabled if explicitly requested via a command line switch. > Maybe I should add -march= and -mtune= to assembler. It sounds like it would be a good idea, although if it is only to support this new feature then you may not want to go that far. Cheers Nick